speeey



(No Model.)

E. A. SPERRY.

MACHINE FOR CUTTING SCREW THREADS. No. 294,092. Patented Feb. 26, 1884.

Wnesses: Jnveniar:

UNTTED STATES PATENT @rrrce.

ELMER'A. SPERRY, OF CORTLAND, NEW YORK, ASSIGNOR TO JESSE- VAN DENBURGH,OF SAMfE PLACE.

MACHINE FOR CUTTING SCREW-THREADS.

SPECIFICATION forming part of Letters Patent No. 294,092, dated February26, 1884.

Application filed September 30, 1882. (No model.) v

To all whom, it may concern:

Be it known that I, ELMER A. SPERRY, a citizen of the United States,residing at Cortland, in the county of Cortland and State of New York,have invented certain new and useful Improvements inScrew-Thread-Gutting Machines; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, and to theletters or figures of reference marked thereon,

which form a part of this specification.

dies are brought into engagement with the blank without being at anytime disconnected from the power.

In the drawings, Figure 1 represents a longitudinal section of themachine. Fig. 2 represents a top elevation of a portion of the ma chine,showing the lever controlling the cam- 7 plates. Fig. 3 represents afront view of the die.

It will be seen from the drawings'that A represents a hollow spindle ofa bolt-machine,

provided at its extremity with a face-flange,

. nal E, as shown.

a, to which are pivoted the die-carriers B B, each of which is providedat its extremity, opposite the pivot, with a radially -projecting pin,1), adapted to operate in the slots provided in the cam-plates O 0.These plates project from the shifting-sleeve D, which is loose on theshaft, and is grooved to receive the ring (1, for attachment of theshifting-lever E,which is pivoted, suitably, to a projection of thejour- The flange a is provided on its periphery with slots ordepressions, in which are fitted the cam-plates O O, which slide thereinlongitudinally, but are rigidly insured thereby against transversestrain. The dies B B are adjustably or otherwise attached to theircarriers B B, and are brought in and out of engagement with the work bya swinging movement of said carriers about their pivots b b. The diesare shown in their extreme open positions in Fig. 3 by dotted lines. Thepulley G is attached rigidly to theshaft, and no portion of the system,whether in or out of operation, is at any time disengaged from thepower.

For supplying constant lubricant to the dies I have devised a pump, nowto be described.

The base H of the machine forms a-reservoir for the lubricant, and isprovided at the back in its floor with a depression or well, (7, theaperture of which is screw-threaded, and provided with the cylindricalportion of a curved casting, I. The bore of said cylindrical portionforms the pump-barrel, .and is provi'ded'with a loose plunger, 0, drivenfrom the eccentric f, secured to shaft A, as shown. The perforation in'the outward end of the casting I is threaded, to receive the piping 9,leading to the nozzle 9. The inserted end of said pipe 9 serves toretain the ball 71. in a suitable counterbore below, this forming theonly valve of the pump. The pump-barrel is pierced at 'i a little belowthe plunger when in its uppermost position, but in such proximitythereto that it is entirely coveredthereby before said plunger hascompleted its downward stroke. An annulus, j, of wire-cloth or othersuitable screen, is provided over the well, to prevent egress of foreignsubstances. The operation of the devices detailed above is as follows:The blank or work is secured in a chuck of usual form. The machinereceives a constant rotation in one direction from the pulley G. Thedies being closed, the blank is fed to them, and when the operation hasproceeded sufliciently they are disengaged from said blank, while stillin constant rotation, by manipulating the lever E and sliding the collar D and cam-plates O C to such a position that the pins 1) b, byengagement in the camslots, rock the die-carriers B B to their outermostposition. (Shown in dotted lines in Fig. 3.) The threaded blank is thenwithdrawn and a new one provided, and the operation repeated.

The pump operates as follows: At each upward stroke of the plunger, whenits lower extremity has passed and opened passage i, the lubricant, bygravity, fills the barrel, and

in that portion of the stroke below said opening said plunger forces itout to the tube 9, past the valve 71, which retains it during the upwardstroke of the plunger, as can readily be understood. A detachable panwith a perforated bottom is provided under the dies, for the retentionand ready removal of chips.

The pump, per 80, is not sought to be covered in this application, asthat device in its relation as shown is designed to make subjectmatterfor a separate application.

Many slight alterations may be made in the detailed construction withoutdeparting from the spirit of the invention. For instance, gearing may beused, instead of the pulley G, in

the largermachines, and a hand wheel or crank in hand-machines.

By my construction I do away with the necessity of a clutch such as isusually employed in similar machines.

I am aware that the dies in open-die machines have been operated bymeans of cam plates and slots; but the movement of parts,

:BED EJDSPLB effecting the change simultaneously, brought slidingcanrplates O C, the eccentrics f and pulley G, the whole being adaptedto throw the dies in and out of action without disconnecting the power,as and for the purposes set forth.

I11 testimony whereof I afiix my signature in presence of two witnesses.

ELMER A. SPERR-Y.

\Vitnesses:

'M. M. WATERs, J. MCLERNAN.

